The present invention is directed to structure for use in maintaining a patient in a desired position during examination and treatment, including medical procedures such as imaging and surgery. In particular, the present invention is directed to such a structure that allows a surgeon to selectively position the patient for convenient access to the surgery site and that provides for manipulation of the patient during surgery including digitally coordinated tilting, pivoting, and angulating or bending of a trunk and/or a joint of a patient in a supine, prone, or lateral position.
Current surgical practice incorporates imaging techniques and technologies throughout the course of patient examination, diagnosis, and treatment. For example, minimally invasive surgical techniques, such as percutaneous insertion of spinal implants, involve small incisions that are guided by continuous or repeated intra-operative imaging. These images can be processed using computer software that produces three dimensional images for reference by the surgeon during the course of the procedure. If the patient support surface is not radiolucent or compatible with the imaging technologies, it may be necessary to interrupt the surgery periodically in order to remove the patient to a separate surface for imaging followed by transfer back to the operating support surface for resumption of the surgical procedure. Such patient transfers for imaging purposes may be avoided by employing radiolucent and other imaging compatible patient support systems. The patient support system should be constructed to permit unobstructed movement of the imaging equipment and other surgical equipment around, over, and under the patient throughout the course of the surgical procedure without contamination of the sterile field.
It is also necessary that the patient support system be constructed to provide optimum access to the surgical field by the surgery team. Some procedures require positioning of portions of the patient's body in different ways at different times during the procedure. Some procedures, for example, spinal surgery, involve access through more than one surgical site or field. Since all of these fields may not be in the same plane or anatomical location, the patient support surfaces should be adjustable and capable of providing support in different planes for different parts of the patient's body as well as different positions or alignments for a given part of the body. The support surface should be adjustable to provide support in separate planes and in different alignments for the head and upper trunk portion of the patient's body, the lower trunk and pelvic portion of the body, as well as each of the limbs independently.
Certain types of surgery, such as orthopedic surgery, may require that the patient or a part of the patient be repositioned during the procedure while in some cases maintaining the sterile field. Where surgery is directed toward motion preservation procedures, such as by installation of artificial joints, spinal ligaments, and total disc prostheses, for example, the surgeon must be able to manipulate certain joints while supporting selected portions of the patient's body during surgery in order to facilitate the procedure. It is also desirable to be able to test the range of motion of the surgically repaired or stabilized joint and to observe the gliding movement of the reconstructed articulating prosthetic surfaces or the tension and flexibility of artificial ligaments, spacers, and other types of dynamic stabilizers before incisions are closed. Such manipulation can be used, for example, to verify the correct positioning and function of an implanted prosthetic disc, spinal dynamic longitudinal connecting member, interspinous spacer, or joint replacement during a surgical procedure. Where manipulation discloses binding, sub-optimal position, or even crushing of the adjacent vertebrae, for example, as may occur with osteoporosis, the prosthesis can be removed and the adjacent vertebrae fused while the patient remains anesthetized. Injury which might otherwise have resulted from a “trial” use of the implant post-operatively will be avoided, along with the need for a second round of anesthesia and surgery to remove the implant or prosthesis and perform the revision, fusion, or corrective surgery.
There is a need for a patient support surface that can be rotated, articulated, and angulated in a coordinated manner so that the patient can be moved from a prone to a supine position or from a prone to a 90° position and whereby intra-operative extension and flexion of at least a portion of the spinal column can be achieved. The patient support surface must also be capable of easy, selective, and coordinated adjustment without necessitating removal of the patient or causing substantial interruption of the procedure.
The patient support may be articulated upwardly and downwardly at the patient's hips during such a surgical procedure. Such patient support articulation results in an undesirable extension or compression, respectively, of at least a portion of the patient's body. Thus, there is a need for translation compensation of the extended or compressed portion of the patient's body that is coordinated with articulation of the patient support, so as to prevent such undesirable compression or extension. Such translation compensation can be provided by a slide mechanism supporting either an upper or lower portion of the patient's body, or both, which moves toward patient support articulation hinge when the patient support is articulated upwardly or away from the hinge when the patient support is articulated downwardly. The slide mechanism can be mechanically linked to the portions of the patient support so that the slide mechanism is moved in proportion to the hinge angle of the patient support. A disadvantage of a mechanically linked translation compensation mechanism is that the proportionality between the linear movement of the slide mechanism and the hinge angle is usually fixed.
For certain types of surgical procedures, for example spinal surgeries, it may be desirable to position the patient for sequential anterior and posterior procedures. The patient support surface should also be capable of rotation about an axis in order to provide correct positioning of the patient and optimum accessibility for the surgeon as well as imaging equipment during such sequential procedures.
Orthopedic procedures may require the use of traction equipment such as cables, tongs, pulleys, and weights. The patient support system must include structure for anchoring such equipment, and it must provide adequate support to withstand unequal forces generated by traction against such equipment.
Articulated robotic arms are increasingly employed to perform surgical techniques. These units are generally designed to move short distances and to perform very precise work. Reliance on the patient support structure to perform any necessary gross movement of the patient can be beneficial, especially if the movements are synchronized or coordinated. Such units require a surgical support surface capable of smoothly performing the multi-directional movements which would otherwise be performed by trained medical personnel. There is, thus, a need for integration between the robotics technology and the patient positioning technology.
While conventional operating tables generally include structure that permits tilting or rotation of a patient support surface about a longitudinal axis, previous surgical support devices have attempted to address the need for access by providing a cantilevered patient support surface on one end. Such designs typically employ either a massive base to counterbalance the extended support member or a large overhead frame structure to provide support from above. The enlarged base members associated with such cantilever designs are problematic in that they can and do obstruct the movement of C-arm and O-arm mobile fluoroscopic imaging devices and other equipment. Surgical tables with overhead frame structures are bulky and may require the use of dedicated operating rooms, since in some cases they cannot be moved easily out of the way. Neither of these designs is easily portable or storable.
Thus, there remains a need for a patient support system that provides easy access for personnel and equipment, that can be easily and quickly positioned and repositioned in multiple planes without the use of massive counterbalancing support structure, and that does not require use of a dedicated operating room.